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Rationally Speaking is a blog maintained by Prof. Massimo Pigliucci, a philosopher at the City University of New York. The blog reflects the Enlightenment figure Marquis de Condorcet's idea of what a public intellectual (yes, we know, that's such a bad word) ought to be: someone who devotes himself to "the tracking down of prejudices in the hiding places where priests, the schools, the government, and all long-established institutions had gathered and protected them." You're welcome. Please notice that the contents of this blog can be reprinted under the standard Creative Commons license.

Friday, April 15, 2011

Evolution as pseudoscience?

by Massimo Pigliucci

Don't worry, despite the title of this post, I have not suddenly gone creationist. Rather, I have been intrigued by an essay by my colleague Michael Ruse, entitled “Evolution and the idea of social progress,” published in a collection that I am reviewing, Biology and Ideology from Descartes to Dawkins (gotta love the title!), edited by Denis Alexander and Ronald Numbers.

Ruse, who has arguably written more than anyone else on the planet about the history and philosophy of Darwinism, is also contributing to a large collection of new essays on the demarcation problem (the distinction between science and pseudoscience), that Maarten Boudry and I are putting together for the University of Chicago Press (provisional title: The Philosophy of Pseudoscience: Reconsidering the Demarcation Problem — stay tuned).

Ruse's essay in the Alexander-Numbers collection questions the received story about the early evolution of evolutionary theory, which sees the stuff that immediately preceded Darwin — from Lamarck to Erasmus Darwin — as protoscience, the immature version of the full fledged science that biology became after Chuck's publication of the Origin of Species. Instead, Ruse thinks that pre-Darwinian evolutionists really engaged in pseudoscience, and that it took a very conscious and precise effort on Darwin’s part to sweep away all the garbage and establish a discipline with empirical and theoretical content analogous to that of the chemistry and physics of the time.

Ruse asserts that many serious intellectuals of the late 18th and early 19th century actually thought of evolution as pseudoscience, and he is careful to point out that the term “pseudoscience” had been used at least since 1843 (by the physiologist Francois Magendie), while the concept was prominently on display during the historical investigation of mesmerism ordered in 1784 by King Louis XVI of France and jointly carried out by Antoine Lavoisier and Benjamin Franklin.

Ruse’s somewhat surprising yet intriguing claim is that “before Charles Darwin, evolution was an epiphenomenon of the ideology of [social] progress, a pseudoscience and seen as such. Liked by some for that very reason, despised by others for that very reason.”

Indeed, the link between evolution and the idea of human social-cultural progress was very strong before Darwin, and was one of the main things Darwin got rid of. The encyclopedist Denis Diderot was typical in this respect: “The Tahitian is at a primary stage in the development of the world, the European is at its old age. The interval separating us is greater than that between the new-born child and the decrepit old man.” Similar nonsensical views can be found in Lamarck, Erasmus, and Chambers, the anonymous author of The Vestiges of the Natural History of Creation, usually considered the last protoscientific book on evolution to precede the Origin.

On the other side of the divide were social conservatives like the great anatomist George Cuvier, who rejected the idea of evolution — according to Ruse — not as much on scientific grounds as on political and ideological ones. Indeed, books like Erasmus’ Zoonomia and Chambers’ Vestiges were simply not much better than pseudoscientific treatises on, say, alchemy before the advent of modern chemistry.

One of Ruse’s interesting points is that people were well aware of this sorry situation, so much so that astronomer John Herschel referred to the question of the history of life as “the mystery of mysteries,” a phrase consciously adopted by Darwin in the Origin. Darwin set out to solve that mystery under the influence of three great thinkers: Newton, the above mentioned Herschel, and the philosopher William Whewell (whom Darwin knew and assiduously frequented in his youth). Let us take them briefly one by one to see exactly what Ruse means.

Darwin was a graduate of the University of Cambridge, which had also been Newton’s home. Chuck got drilled early on during his Cambridge education with the idea that good science is about finding mechanisms (vera causa), something like the idea of gravitational attraction underpinning Newtonian mechanics. He reflected that all the talk of evolution up to then — including his grandfather’s — was empty, without a mechanism that could turn the idea into a scientific research program.

The second important influence was Herschel’s Preliminary Discourse on the Study of Natural Philosophy, published in 1831 and read by Darwin shortly thereafter, in which Herschel sets out to give his own take on what today we would call the demarcation problem, i.e. what methodology is distinctive of good science. One of Herschel’s points was to stress the usefulness of analogical reasoning (more on this in a moment).

Finally, and perhaps most crucially, Darwin also read (twice!) Whewell’s History of the Inductive Sciences, which appeared in 1837. In it, Whewell sets out his notion that good scientific inductive reasoning proceeds by a consilience of ideas, a situation in which multiple independent lines of evidence point to the same conclusion.

Here is the cool thing: the first part of the Origin, where Darwin introduces the concept of natural selection by way of analogy with artificial selection can be read as the result of Herschel’s influence (natural selection is the vera causa of evolution), while the second part of the book, constituting Darwin's famous “long argument,” applies Whewell’s method of consilience by bringing in evidence from a number of disparate fields, from embryology to paleontology to biogeography.

What, then, happened to the strict coupling of the ideas of social and biological progress that had preceded Darwin? While he still believed in the former, the latter was no longer an integral part of evolution, because natural selection makes things “better” only in a relative fashion. There is no meaningful sense in which, say, a large brain is better than very fast legs or sharp claws, as long as you still manage to have dinner and avoid being dinner by the end of the day (or, more precisely, by the time you reproduce).

Ruse’s claim that evolution transitioned not from protoscience to science, but from pseudoscience, makes sense to me given the historical and philosophical developments. It wasn’t the first time either. Just think about the already mentioned shift from alchemy to chemistry. Of course, the distinction between pseudoscience and protoscience is itself fuzzy, but we do have what I think are clear examples of the latter that cannot reasonably be confused with the former, SETI for one, and arguably Ptolemaic astronomy. We also have pretty obvious instances of pseudoscience (the usual suspects: astrology, ufology, etc.), so the distinction — as long as it is not stretched beyond usefulness — is interesting and defensible.

It is amusing to speculate which, if any, of the modern pseudosciences (cryonics, singularitarianism) might turn out to be able to transition in one form or another to actual sciences. To do so, they may need to find their philosophically and scientifically savvy Darwin, and a likely bet — if history teaches us anything — is that, should they succeed in this transition, their mature form will look as different from the original as chemistry and alchemy. Or as Darwinism and pre-Darwinian evolutionism.

Great summary; if you don't mind, I'm going to seize on one point and jump on my soapbox for a moment.

Darwin called the Origin "one long argument," but I really do think that recognizing that the book contains (at least) two arguments could help to dispel that whole "just a theory" canard. The first half of the book is devoted to demonstrating that natural selection is the true cause of evolution; vera causa arguments require proof that the cause's effect be demonstrated as fact, so the second half of the book is devoted to a demonstration that evolution has really happened. In other words, evolution is a demonstrable fact and natural selection is the theory that explains that fact, just as the motion of the planets is a fact and gravity is a theory that explains it.

This is why my hackles get raised whenever I read something in the popular press about the "theory of evolution." I understand that the copy reads easier than does "the theory of evolution by means of natural selection," but this is a case in which simplifying the language obscures an important conceptual point (much to everyone's detriment).

They should just stop using the word 'theory' altogether and use the word 'model' instead since that is what they are Evolution Model, Gravity Model, Germ Model etc.. The best model presently supported by the evidence and that word is good enough for the Standard Model of physics so evolution would be in good company.

Nice post. I like hearing what Michael Ruse has been up to. He seems to be breaking new ground.

Two comments.

First. Cryogenics is the study of the production of low temperatures and the behavior of materials at those temperatures. It is a legitimate branch of physics and has been for a long time. I think you meant 'cryonics'.

Second. The Singularity means different things to different people. It is uncharitable to dismiss all "singularitarians" by debunking Kurzweil. He is low hanging fruit. Reach for something higher.

I don't know enough about evolutionary ideas that preceded Darwin to have an opinion about how to describe them, but I wonder whether pseudoscience or protoscience are the only possibilities. Perhaps they were philosophy or politics or history or something else. Darwin didn't invent a new science he revolutionized biology which was an old science.

Charles wrote, "Second. The Singularity means different things to different people. It is uncharitable to dismiss all "singularitarians" by debunking Kurzweil. He is low hanging fruit. Reach for something higher."

Let's modify but maintain the sentiment..."Second. God means different things to different people. It is uncharitable to dismiss all "theists" by debunking Kent Hovind. He is low hanging fruit. Reach for something higher."

"But Mr. Darwin's views have one peculiar merit; and that is, that they are perfectly consistent with an array of facts which are utterly inconsistent with, and fatal to, any other hypothesis of progressive modification which has yet been advanced. It is one peculiarity of Mr. Darwin's hypothesis that it involves no necessary progression or incessant modification, and that it is perfectly consistent with the persistence for any length of time of a given primitive stock, contemporaneously with its modifications."-T.H. Huxley, Six Lectures to Working Men, 1863[On Our Knowledge of the Causes of the Phenomena of Organic Nature, in Darwinia]

As for singularitarianism, I keep hearing that there are higher hanging fruits, but I don't see them, would you mind giving me an example?

CW,

I think the study of the origin of life is a protoscience. However, there is a good possibility that it will remain stuck there forever, considering the very low likelihood that we will ever recover sufficient historical traces to actually be able to figure out what happened.

Harry,

ancient Greek notions of evolution were at the very least protoscientific, but they may be considered pseudoscientific in the sense intended by Ruse. Frankly, it's hard to tell, considering that we only have fragments that aren't exactly clear.

"However, there is a good possibility that it will remain stuck there forever, considering the very low likelihood that we will ever recover sufficient historical traces to actually be able to figure out what happened."

I think at best scientists may eventually figure out one or more ways that it could have happened with no way to verify that it did happen that way. You may be sure the headlines on such a discovery will not contain that nuance.

How are those pseudosciences? One is essentially an unsolved engineering problem, the other a movement that would probably describe itself as philosophical, awareness-raising or perhaps even political. I would not be aware that they make any claims of being a science, but at most of being supported by the knowledge produced by already established sciences.

I also once again doubt the usefulness of this whole approach. There are ideas (models?) about what has happened and how, and once somebody has an idea that fits our observations better, we tentatively accept it and reject the previous one. Thus, goddidit was a reasonable explanation when but only as long as it was the only one anybody could come up with, and pre-Darwinian ideas of evolution were reasonable when Darwin had not yet made his case.

To me, it only turns into pseudoscience when somebody has the better explanation available and then rejects it because of some bias. But saying somebody in 1780 is a pseudoscientist because they did not immediately come up with natural selection, or because they did not use the scientific method as refined in the 20th century is what they call a Whiggish view of history.

Leonard Finkelman,

Agreed, but do you believe there would be significantly less creationists if this was expressed more precisely? Nah.

Re: singularitarianism... I don't know that I'd call myself a singularitarian, but I understand the theoretical argument for it. Allow me to lay it out.

We baseline humans will probably have a maximum capability in terms of how high an artificial (or semiartificial) intellect we can create. Assuming a constant relationship between base intellect x0 and maximum created intellect x1, we can express it as x1 = V * x1. Here V is a constant which we can call the Vinge factor (after Vernor Vinge). Now, if V =< 1, we can at best match our own intellects with our creations, be they biological or synthetic. Humanity is as high as we'll get in terms of intellect. But if V > 1, then those creations will be smarter than us. Then x0 < x1 < x2 < x3, etc. as our creations in turn create new forms of intellect.

Barring physical limitations on processing speed (which we seem to have a talent for finding ways around), it can then be assumed that there exists a generation n where xn is as much above x0 as x0 is above, say, the intellect of chimpanzees. Such an occurrence would put baseline humans on the sidelines permanently (we do not make policy decisions with advice from chimps, either, after all), and leave them without the necessary understanding to affect the world.

Now, the problems with this approach include that we don't actually have any idea whether we can even build strong AI (as in, AI that is functionally equivalent to human capability, speed notwithstanding). My suspicion is that we can, but that will have to shake out over the next decades as computer science goes to town on that problem. Then there's the question of whether a linear relationship truly is the case. A logarithmic or asymptotic relationship would have similar effects to that of V =< 1, above, just at a higher level of overall intellect. There's other open questions, and there's a lot of speculation.

Meanwhile, Kurzweil is an asshat who is making it harder for those of us who find it fascinating and legitimate to study...

yes, I know you don't like demarcation projects, though I'm sure you like the fact that your local gas station is clearly labeled so not to be confused with the hospital nearby...

Anyway, cryogenics is - so far - a pseudoscience because of it's culture and the claims it makes. The same with singularitarianism. And no, "goddidit" is not an explanation by any meaningful sense of the word "explanation."

As for evolution before Darwin, Ruse's point is not just that they got it wrong, it's that there was no science to speak of, it was a jumble of mysticism and socio-political hopes.

Gert,

what you wrote, I'm afraid, doesn't seem to me to be any more of a higher hanging fruit than Kurzweil. You yourself have immediately pointed out some of the obvious problems, and while the language is different, the concepts seems to be the same, and therefore equally silly.

Alex,My concern isn't with creationists (their souls are, ironically enough, beyond saving); it's with grade school students whose teachers have only the vaguest idea of how to teach evolutionary biology. Considering that the Lamarckian giraffe is still taught as a paradigmatic case of Darwinian evolution, it's pretty clear that students aren't getting the right view of pattern or process in evolution.

Massimo, This is somewhat off topic, but it reminded me of a question that arose when reading Origin a couple of years ago. Darwin seems to use “natural selection” in two distinct senses at various points in the work. (I don’t have my copy handy to offer any examples…) Namely, in some instances he used it in the sense of the phenomenon itself needing explained and in others as an explanation for some phenomenon. The former seems like a formal cause and the latter an efficient cause, and the subtle flip-flop in usage left me with an uneasy feeling, philosophically speaking. Thinking of “natural selection” as formal cause makes more sense to me, but it seems Origin makes the case that it is efficient cause. (Most biologists I know think of “natural selection” as efficient cause, and they do not seem interested in the distinction.) What are your thoughts?

Wonderful post, Massimo -- this is a fascinating argument and one that I think accords with my long-held intuition that "Social Darwinism" is an egregious misnomer for an outlook that existed well before Darwin, and that Darwin was working against. I look forward to reading Ruse's essay.

Well yes, by all means go ahead and define science with Popperian and Kuhnian criteria, and then point and laugh at those who did research before Popper was even born. But again: what is it good for? Either it results in the trivial insight that our understanding and methods improve over time, or it is Whiggish, akin to faulting Archimedes for not inventing nuclear fission or for not campaigning against slavery.

Leonard Finkelman,

That sounds pretty awful. Well, I was taught in a different country, and there Lamarck's giraffe was the example for the nice idea but ultimately wrong that people tried to come up with before Darwin.

Verym interesting. You say that one of the things that made Darwin's contribution be science vs. pseudoscience was his rejection of the idea of progress. But may there not be a form of "progress" in increasing complexity? We see, for example, a general development in life toward greater complexity. Of course, this isn't perfect, and it isn't without setbacks, but there is a certain trend toward greater complexity along certain lines of evolutionary development. Archebacteria and eubacteria preceded eukaryotes, single-celled eukaryotes preceded polycellular organisms, which prededed multicellular organisms, etc. on up to humans, who have the most complex brains and social organizations. Nothing guarantees this continuation, of course, any more than there is a guarantee that we will continue to be around (like I said, setbacks are possible), but there does seem to be a general trend in the universe toward greater complexity along certain lines. (Hydrogen, helium, and lithium preceded larger atoms, etc. up through life.) Psychologist Clare Graves and a few others have argued for levels of increasing psychological and social complexity. How does this fit into the argument that Darwin's contribution was scientific precisely because it rejected progress? Or was it because it rejected a particular idea of progress? Or, considering the fact that "progress" is a normative idea, should be reject the idea of progress in favor of emergent complexity? (I'm hardly against this latter suggestion.)

> Namely, in some instances he used it in the sense of the phenomenon itself needing explained and in others as an explanation for some phenomenon. <

Yes, that sort of confusion is still around today, and there is a now substantial literature on the various ways of thinking about natural selection. Jonathan Kaplan and I addressed some of this in two chapters of Making Sense of Evolution.

> Thinking of “natural selection” as formal cause makes more sense to me, but it seems Origin makes the case that it is efficient cause. <

Right, if by natural selection we mean the population-level description of some evolutionary processes, then it is best to think of it as a formal cause. But if one is talking about individual-level selective episodes, which are causally highly heterogeneous, then that's more like an efficient cause.

Alex,

> by all means go ahead and define science with Popperian and Kuhnian criteria, and then point and laugh at those who did research before Popper was even born. But again: what is it good for? <

First, Ruse is not trying to apply either Popperian or Kuhnian criteria. As he points out (and I wrote in the post) both the term and the concept of pseudoscience had already been around for a while by the time pre-Darwinian evolutionists started writing.

Second, I keep having a hard time wrapping my head around your antipathy for any demarcation project, no matter how nuanced. Surely as a biologist you classify things, and think that there is both a pragmatic reason for doing it and even some intrinsic intellectual interest in how it can be done. I don't see the difference.

that's precisely the Chalmers paper that I said I hope to find some time (possibly this summer) to criticize extensively in a technical forum. I even attended a talk by Chalmers at the Graduate Center not long ago, based on that paper. As far as I can tell, the most appropriate technical term for it is "poppycock."

Troy,

> But may there not be a form of "progress" in increasing complexity? We see, for example, a general development in life toward greater complexity. <

Nobody questions the increase in complexity over time. But as S.J. Gould nicely explained it (in Full House), how could it have been otherwise? Unless the cosmos and the biosphere were intelligently designed they simply *had* to start simple. And from there there's only one way to go... Moreover, we see reversals in the complexity trend all the time, e.g. in the evolution of parasites. And there is no measurable / meaningful sense in which, say, an elephant is "better" than a bacterium.

Evolutionary biology today has to incorporate soft inheritance, saltational changes due to systemic mutations, and various types of genetic exchange and cooperation.These all challenge the assumptions of the Modern Synthesis. We believe that rather than trying to continue to work within the framework of a Synthesis that was made in the middle of the last century, we now need a new type of evolutionarytheory, one that acknowledges Darwinian, Lamarckian and saltational processes.

right, and I may sound too cranky. Obviously there must be science and non-science, and it is essential to be able to distinguish it. But it might also be argued that the fuzziness of our classifications should reflect the fuzziness of reality.

There is a certain degree to which what Gould said is true, but it seems to me that it's oly superficially true. Let us deal with organisms. Why, once the first organsism come about, do they have to become more complex? Couldn't they have just retained the same level of complexity? There is nothing in natural selection per se that suggests complexity should emerge. On the other hand, there do seem to be drivers of complexity within nature (strange attractors, catastrophe theory, emergence, complexity theory, etc. deal with these things). The tendency toward complexity is just that, a tendency. That doesn't mean there aren't selective pressures for certain kinds of reversals, such as parasitism. Or that there are not contingent events that don't care about tendencies (like giant asteroids). But it seems to me that one cannot deny the fact that ever-greater complexity has tended to emerge throughout the history of the universe. It comes about as the underlying paradoxical tensions (various forms of attraction and repulsion occuring simultaneously) play themselves out. QUite frankly, I don't think Gould was quite dialectical enough in his biology.

Gould was less superficial than you think. First of all, the world *was* in fact inhabited by simple unicellular life forms for billions of years, i.e. for the majority of its history. Second, one of the ideas that has been proposed is that as some point all the available ecological niches get filled, so that if an increase in complexity (say, pro- to eukariotic cells) can open up new niches than it is favored by selection.

Yes, there are phenomena that can increase complexity in the world, but there doesn't seem to be a need for special explanations or for any teleological thinking. Sometimes complexity increases, for the reasons stated above.

I think the difference between what I say and what Kurzweil says should be immediately clear: I don't claim to preach the gospel truth. :-)

The problem with a concept like the singularity, or the effects of strong AI, is that the whole mess is conjectural. We don't, as said, even know if we can build the damn things yet! :-) Of course, it might still be worthwhile to conjecture a little, keeping an open mind, as it were - after all, if the conjecture ends up bearing out, it'll be a quite huge change of how we live our lives.

In the end, it is an article of faith, for me, that we can build strong AI, and that we can eventually build it stronger than human intellect. But it is just that: A belief. It is not wholly unfounded, however: I'm a computer scientist (of newer vintage and far less illustrious pedigree than Kurzweil, but I, contrariwise, try not to have the brainworms), and I've worked on AI a little bit. Nothing deeply serious, but enough to get a distinct sense that what our brain does is nothing magical or arcane - nothing we can't emulate with technology. Then it becomes a question of processing power, and well, there development shows no signs of stopping, or even ceasing to accelerate, any time soon.

I'm pretty sure I made no mention of teleology. I'm proposing a kind of nonteleological progress. One doesn't have to know where you're going to recognize that there is some sort of forward movement. One doesn't even have to have a goal to move forward. There seems to be a tendency in the universe for greater complexity. Something -- some law of the universe, perhaps -- is driving it.

well, if you reject sensible explanations for increases in complexity (not "progress," which is really meaningless outside of human values), then teleology becomes the obvious option. And I disagree, one does have to have a goal if one wants to talk about progress, otherwise it's just change, which is fine by me.

Well, I am happy to do away with the term "progress" if it necessarily contains teleology as part of its definition. So let me ask you, since we agree that progress is not a good term to use: what term would you use to describe the tendency in the universe toward increasing complexity (understanding that a tendency does not mean reductions in complexity are impossible, or even unlikely)? There are, after all, different kinds of change. There is lateral change, change that results in an increase in complexity, and change that results in a decrease in complexity. A term for each would be useful, I think.

I'm confused, what exact claims of cryonics are you referring to as evidence that it is pseudoscience instead of protoscience? We don't know if cryonics saves people from death, but we also don't know if aliens exist. A positive comparison with SETI seems reasonable.

I'm also not sure where you get the impression that the main culture of cryonics is one that favors pseudoscience. Could be selection bias on my part, but it seems like that the majority of people I have met with this interest in common are fairly skeptical. In fact, it is the sort of thing I hesitate to bring up with people who believe in UFOs or ghosts. The kind of superstitious mindset that gets taken in by that sort of thing does not seem to be very compatible with cryonics.

It would be interesting to know from an outside perspective, exactly what seemingly needs to be changed for cryonics to be something other than pseudo-science? I would think it unreasonable to say that cryonics at its simplest -- preserving today's corpses with the intent of future reanimation -- is in and of itself inherently unscientific. So where does this perception originate?

The practice does carry an implied claim (the claim that it will work), but one that I think is consistently framed and understood within the community as a claim *to be tested*, and one which is based on, and gains (or loses) its strength in actual evidence in the physical world regarding low temperature physics and the structural, neurological basis for human intelligence.